International Criminal Court prosecutor Karim Khan said Monday that the ICC "won't hesitate to act" over possible war crimes in Ukraine, as ministers from more than 40 countries met in London.

China on Monday called on the International Criminal Court to avoid what it called "double standards" and respect immunity for heads of state, after the tribunal issued an arrest warrant for Russian leader Vladimir Putin on war crimes charges.

Justice ministers from more than 40 countries will meet in London on Monday to discuss boosting international support for the International Criminal Court’s (ICC) as it investigates possible war crimes in the Ukraine conflict. 

Russian President Vladimir Putin made a surprise visit to Mariupol, state media reported Sunday, his first to the city since it was captured after a lengthy siege at the start of Moscow's offensive in Ukraine. 

The International Criminal Court has taken the major step of issuing an arrest warrant for Vladimir Putin over the Ukraine war.